PDCD1 and cancer: The KEGG pathway related to NOD-like receptor signaling pathway, RIG-I-like receptor signaling pathway, Toll-like receptor signaling pathway, NF-kappa B signaling pathway, C-type lectin receptor signaling pathway, PD-L1 expression, and PD-1 checkpoint pathway in cancer and Antigen processing and presentation were also significantly enriched (Figure 13B).